Question

which is better base and why? -C(trible bond)-N or CH3O- ?

Answer 1

In -C$\equiv$N both atoms are sp hybridized. The nitrogen's electron pair dwells very close to the nucleus in a sp orbital thus being very unaccesible. Therefore, this is a very weak base. On the other hand, CH₃O⁻ is the conjugate base of methanol CH₃OH. Methanol does not dissociate in water i. e. it is a very weak acid. Therefore, CH₃O⁻ is a strong base.

Answer: CH₃O⁻ is a better base.